Treatments no one wants

Most experiments in development economics involve giving the treatment group something they want (e.g. cash, health care, schooling for their kids) or at least offering something they might want and can choose whether or not to take up (e.g. business training, financial education). Indeed among the most common justifications for randomization is that there is not enough of the treatment for everyone who wants it, leading to oversubscription or randomized phase-in designs.